generic_netlink 用法

参考资料：

https://wiki.linuxfoundation.org/networking/generic_netlink_howto

generic_netlink 框架

     +---------------------+      +---------------------+
     | () application "A" |      | () application "B" |
     +------+--------------+      +--------------+------+
            |                                    |
            \                                    /
             \                                  /
              |                                |
      +-------+--------------------------------+-------+
      |        :                               :       |   user-space
 =====+        :   ()  kernel socket API      :       +================
      |        :                               :       |   kernel-space
      +--------+-------------------------------+-------+
               |                               |
         +-----+-------------------------------+----+
         |        ()  Netlink subsystem            |
         +---------------------+--------------------+
                               |
         +---------------------+--------------------+
         |       () Generic Netlink bus            |
         +--+--------------------------+-------+----+
            |                          |       |
    +-------+---------+                |       |
    |  () controller |               /         \
    +-----------------+              /           \
                                     |           |
                  +------------------+--+     +--+------------------+
                  | () kernel user "X" |     | () kernel user "Y" |
                  +---------------------+     +---------------------+